Speaking to Vulture, Jackman reveals his workout regimen, saying, "Weirdly, this was almost more physical in a way than an X-Men movie! I was spending even longer in the gym -- like three hours in the gym -- because I needed to be as emaciated as possible, but still keep some muscle on for Jean Valjean. He's actually written as an ox of a man, so I had to eat seven times a day with no carbohydrates, but then you had the exercise. I'd wake up and do 45 minutes of [cardio] on an empty stomach, eat something, go to the gym, do a vocal warm-up, and then after lunch I'd go back to the gym again. Otherwise, I'd just become skin and bones."

Fortunately, the Tony Award-winner has gotten back to his fighting weight as he prepares to don the claws once again in The Wolverine.